機器
blue
business
close
clouds
connection
construction
control
crude
drilling
economy
engineering
equipment
factory
faucet
field
fossil
fuel
gas
gasoline
generation
industrial
iron
junction
line
manifold
metal
natural
oil
patch
petroleum
pipe
pipeline
piping
plant
plumbing
power
powerful
red
resource
set
sky
steel
support
technology
tube
valve
well
wheel
work